This invention relates to combine harvesters and, in particular, to rotors for axial flow combine harvesters.
Axial flow combine harvesters offer superior performance in harvesting grain crops. These harvesters typically employ a rotor, usually orientated fore and aft, in the harvester. The rotor has a plurality of projections which thresh the crop as the crop passes along the rotor. There is usually an impeller at the front of the rotor which has the task of orienting the crop properly and feeding it towards the rotor. However some crops ball up or knot instead of feeding properly towards the rotor. For example, this typically occurs with crops such as hemp.
U.S. Pat. No. 5,497,605 to Underwood shows a hook-shaped impeller blade.
U.S. Pat. No. 5,125,871 to Gorden shows an impeller with a space behind the blades. This is also shown in U.S. Pat. No. 3,982,548 to DePauw et al.
U.S. Pat. No. 5,045,025 to Underwood shows hook-shaped impeller blades.
However there still remains a need for an improved axial flow combine harvester and for an improved impeller to be used in conjunction with the rotor thereof, which solves the problem of certain crops, such as hemp, being improperly fed into the rotor.
According to one aspect of the invention, there is provided an impeller for a rotor of an axial flow combine harvester. The rotor has a front end and is rotatable in a specified rotational direction during normal operation of the harvester. The impeller comprises a front, a rear and a mount for fitting the impeller on the rotor with the rear of the impeller adjacent to the front end of the rotor, and a pair of impeller blades extending radially outwards from the mount. The impeller blades are hook-shaped when viewed from the front of the impeller with outer ends projecting in the rotational direction of the rotor.
According to another aspect of the invention, there is provided a combination impeller and a rotor for an axial flow combine harvester. The rotor has a front end and is rotatable in a specified rotational direction during normal operation of the harvester. The impeller comprises a front a rear, a mount for fitting the impeller on the rotor with the rear of the impeller adjacent to the front end of the rotor, and a pair of impeller blades extending radially outwards from the mount. The impeller blades are hook-shaped when viewed from the front of the impeller with outer ends projecting in the rotational direction of the rotor.
According to a further aspect of the invention, there is provided an axial flow combine harvester having a combination impeller and a rotor. The rotor has a front end and is rotatable in a specified rotational direction during normal operation of the combine harvester. The impeller comprises a front and a rear, a mount for fitting the impeller on the rotor with the rear of the impeller adjacent to the front end of the rotor, and a pair of impeller blades extending radially outwards from the mount. The impeller blades are hook-shaped when viewed from the front of the impeller with outer ends projecting in the rotational direction of the rotor.
The invention offers significant advantages compared to prior art combine harvesters having conventional rotors and impellers for the rotors. It solves the problem of crops balling up on the rotor and instead ensures that all crops, particularly difficult crops such as hemp, feed straight through to the rotor in the axial direction of the rotor.
Moreover, this is accomplished without requiring major modifications to the combine harvester. The impeller and other components of the invention can be retrofitted to standard combine harvesters merely with a few simple tools. Typically this can be accomplished by the farmer himself. Thus considerable frustration and loss of productivity can be removed with relatively inexpensive and easy to install components.